The Definitely Not Coordinating with Stephen Colbert super PAC is at it again. For the third time in as many days, the PAC, now run by comedian Jon Stewart, went up with a 60-second ad on the South Carolina airwaves.

But the latest episode of the satirical trilogy attacks neither a candidate nor a former candidate, instead directing its over-the-top fury at the ferociously negative super PAC ads dominating the GOP primary race, particularly those run by pro-Mitt Romney and pro-Newt Gingrich groups.

So the pro-Colbert super PAC, which supports Comedy Central comedian Stephen Colbert's possible presidential run in South Carolina, is aiming to fight fire with fire.

"Donate today and we'll destroy both these guys [Gingrich and Romney] and their super PACs with the merciless ad torrent so fierce they'll wish they'd never been incorporated," the ad's narrator says as a montage of end-of-the-world images flashes across the screen. "An orgy of pure distortion leaving nothing behind but the clean campaign we all deserve."

The ad will run only twice and only on Charleston, S.C.'s CBS station. It aired once during the 6 a.m. news this morning and will air again during the 11 p.m. hour tonight.

A fourth ad, which CBS station manager Rita Scott said will focus primarily on Colbert himself, will air Thursday.

Colbert and Stewart have spent the past week driving home their point about campaign finance laws that allow super PACs to collect unlimited funds from undisclosed donors and spend them to support candidates, as long as a very fine and very blurry line of coordination between candidate and PAC is not crossed.